Jean-Paul Sartre and Simone de Beauvoir were two of the most brilliant, influential, and scandalous intellectuals of the 20th century, remembered as much for the lives they led as for their influence on the way we think; their committed but notoriously open union created huge controversy in their lifetime. In this biography of Sartre and de Beauvoir's relationship, Edward and Kate Fullbrook offer some original theories related to the extent of de Beauvoir's contribution to their shared ideas, contending that it was de Beauvoir's demand for sexual freedom that dictated the open terms of their relationship and that it was in fact de Beauvoir who was the more powerful thinker of the two.